
Andrew F. answered 01/28/20
Knowledgeable Tutor Specializing in Biology, Biochemistry, and Math
Hi Sarabi,
Remember that a system of equations involves 2 equations with 2 variables each and we can use one equation to help solve the other equation by simplifying the second to one variable. I know that's a confusing way of explaining how they work, so lets go through this question step by step.
So the information we're given is that there are 11 people total. Let's call
X = number of adults
Y = number of children
so: X + Y = 11
Now let's tackle the price part of the problem. Let's multiply the individual ticket prices by the variable representing the number of people, and add them together to get $228
$33X + $15Y = $228
So now we have a system of equations. So let's use the simpler one to "define" a variable in terms of the other. This just means that we need to solve for one variable in one of the equations. Let's solve for Y in the first equation:
X + Y = 11
Y = 11 - X
Now we know that Y = 11 - X, so let's just plug that in for Y in the second equation:
33X + 15Y = 228
33X + 15(11 - X) = 228
Now we can solve for X:
33X + 15(11-X) = 228
33X + (15 x 11 - 15 x X) = 228
33X + 165 - 15X = 228
33X - 15X = 228 - 165
18X = 63
X = 3.5
And now we can solve for Y by plugging in the value of X into the first equation
X + Y = 11
3.5 + Y = 11
Y = 11 - 3.5
Y = 7.5
So now we're in a difficult position. The math worked out, but we can't have "half of an adult" nor "half of a child" so the answer to this problem does not make logical sense. Sorry about that! Hope this helped!